Miles

My first 72 240Z was a father and son project. It was an old SBC v8 conversion that was badly done. There were so many conversion/mechanical/electrical issues with the car that we pulled it completely apart. It was worth the effort though. So I bought another 72 240Z and did the V8 conversion. The car had a severe vibration around 70mph. I ended up pulling the drive shaft and took it to a different shop. The shop discovered that the previous shop had welded the shaft off-axis after they cut it. The shop re-cut/welded and balanced the shaft. No more vibration. The JTR manual is not perfect. Over the years I have found mistakes in the manual, but is does get you off to a good start. Glad you found the vibration. A drive line vibration can make it impossible to enjoy a z car. Mine is down due to a carb (Holley) issue and a leaking 240sx rear caliper. Got ten years out of that caliper (Nugeon)

Do you have the JTR Datsun V8 conversion manual? It covers all of the issues you are having.

delete

TechnoToy Tuning is now selling their Micro Big Rear Bake kit. It includes a parking brake function and will fit under most 14 inch wheels. Has anyone purchased the kit? https://technotoytuning.com/nissan/260z/240260280z-micro-rear-big-brake-kit

Is this a race car?

Why do you need to change out the pivot? Why are you using a 1 inch clutch MC? I have used T5 transmissions on two 240z SBC swaps. Stock Camaro clutch MCs were used on both cars. The pivots looked a bit worn, but since they were NLA I just kept them. No problems in 20 years.

Some members just gutted the stock PV. Don't know how effective it was though.

Does not make sense. If high front bias a PV on the rear would make it worse

I have this set up on my 72 240Z. The front to rear bias is 60% front and 40% rear. A proportioning valve reduces pressure which would make your rear brakes less effective. You absolutely do not need a proportioning valve. So don't install a proportioning valve. My set up includes a 15/16 in 280ZX MC and a 280Z 9 in. dia. booster. Pads are Carbotech AX6. Car is daily driver. Stops like a stock car.

Good find!

Did you put a crush washer under the fitting that connects to the caliper? That may be all you need to do. See picture. 79- 81 280ZX https://www.ebay.com/itm/Goodridge-USA-22070-G-STOP-SS-Braided-Brake-Line-Kit-Fits-79-81-280ZX/202871361712?fits=Model%3A280ZX|Make%3ADatsun&epid=1660785743&hash=item2f3c1350b0:g:1Z0AAOSwXk1eE0OZ

Most of the vendors that sell rear upgrade kits also sell the hoses. Google 240z rear brake upgrade etc https://zcardepot.com/products/rear-disc-brake-hose-braided-stainless-steel-240z-260z-280z?variant=19280846356593# https://www.thezstore.com/page/TZS/PROD/classic21m/24-5581 https://zcardepot.com/products/rear-disc-brake-conversion-kit-240z-260z-280z# https://www.californiadatsun.com/brakes/brake-hoses/

____________________________________________________________________________________________________________________________________ WARNING I recommend that you have an experienced mechanic work with you or do the installation. You can kill yourself or others! _____________________________________________________________________________________________________________________ A caliper that is machined for a banjo fitting and will leak if you screw a regular brake line into it. A banjo fitting is sealed by crush washers. Other brake lines have flared fittings that seal mechanically when mated. You are not plumbing a sink. Never, ever, seal brake lines with any kind of sealant. When properly installed, brake lines seal mechanically. Replace the line you bought with one that has a banjo fitting on the end that connects to the caliper. Be sure to use fresh crush washers under the banjo fitting each time you remove the hose. You can buy the crush washers at any auto parts store. They are either aluminum or copper. If you have drained all of the fluid out of the system and the MC, you will have to remove the MC and bench bleed it. Do a search for instructions. People have trouble bleeding the 280ZX/240SX style calipers. You can remove the caliper, block the pistons from moving, orient the bleeder straight up and also shake the caliper while bleeding the lines and calipers to get all of the air out. Note : if you forget to block the pistons, they will blow out when your helper steps on the pedal and you will be very very very sad. Be safe!

The purpose of the Shed was to keep bad information from appearing when searching Hybridz. Did somebody get their feelings hurt?

What happened to the shed where junk posts went to avoid filling the site with garbage?

Looks like that kit uses either a 240SX or Maxima calipers. You could use stock 240SX or Maxima parking brake cable brackets. But why go to that trouble. You paid for a turn-key kit. The person you talked to blew you off. Other companies sell this same kit: MSA, Silver mine etc. I have done the Maxima and 240SX caliper swaps and used the 240SX/Maxima hangers (cable brackets) with stock parking brake cable. The only issue was that the hole in the 240SX/Maxima bracket was a little bigger than the 240z cable end so the cable was loose in the hole. I have also made custom cable brackets. See picture. The end that the cable attaches to is off my 240z. I cut off the cable end of a 240SX bracket and welded the 240Z cable end onto it. So the 240Z cable end fit perfectly into the bracket. What ever you do don't try to modify the parts they sent you so you can return the kit. Send the kit back. If you really want one of these kits try MSA or Silver mine.

Most of the so called brake upgrades are not upgrades at all. The popular upgrades tend to result in too much front brake bias creating an unbalanced brake system. Many people regret "upgrading" their brakes after discovering that their brake modifications did not improve braking. Stock brakes are designed as a system. Changing one braking component has an unplanned domino effect on the rest of the system. I recommend that you you spend a lot of time reading all of the "brake upgrade" posts before making a decision to modify your car. Look at the posts that deal with brake bias. Well maintained stock brakes are fine for most 240Z applications.

Welcome. Useful information: Download a Factory Service Manual (FSM). http://www.xenonzcar.com/s30.html Download electrical schematics for your car. PDFs are easier to read than those found in books. Some are in color. Buy the book How to Restore Your Datsun Z Car by Wick Humble. It will save you hours of searching for "how to" info. Focus on searching Hybridz as 99% of questions have already been addressed. Start bookmarking Z car parts suppliers. Remember these are 40 year old cars and will need restoration to be safe and drivable. Join ClassicZCars.com website and search there as well. Become well informed about modifications before asking questions. People will be more inclined to answer informed questions Search the forums. Read all of the new member guidelines and FAQs Links: https://www.datsun-240z-upgrades.net/ Recommend the headlight relay harness http://zhome.com/ https://www.zcar.com/ https://www.classiczcars.com/ http://www.zcarparts.com/ http://www.arizonazcar.com/ http://www.jagsthatrun.com/index.html http://www.xenonzcar.com/reference.html

It doesn't hurt to check all of the variables, but ultimately it comes down to how efficient the radiator is.

My stock 72 240z did the exact same thing. I did all of the usual checks for : fan clutch, timing, mixture, collapsing water hose at high RPM, thermostat ratings, no thermostat, flow restrictors (in place of thermostat) , water pump, Camaro radiator (marginal) etc. Had some marginal success, but the temps would still creep up. My brother's brand new 72 240Z over heated at cruise speed! My take is that the stock cooling system is just undersized. Your Z gets hot at high speed where air flow is high. The fan and shroud are necessary at low speed stop and go. At speeds above say 30 or 40 mph, air flow through the radiator is adequate to cool the engine. At some point the fan clutch releases and the fan just spins like a windmill. At 60 mph air is moving at 88ft/sec or 5,280 ft/min. Lots of air moving through the radiator. So the problem must be in the radiator, water flow, timing, mixture, belt slippage etc. Take away: You need a better, higher capacity, radiator, and if using a mechanical fan, make sure that the fan clutch is working. BTW: a mechanical fan is fine. You might want to try the direct-fit radiator from Arizona Z Car and add a shroud to it if stop and go cause the temps to creep up.. This radiator keeps my SBC 350 240z cool in traffic on 100 deg. days.

EDIT

I am following this post. Please update as things progress. I was working on this same approach.

Welcome. Useful information: Download a Factory Service Manual (FSM). http://www.xenonzcar.com/s30.html Download electrical schematics for your car. PDFs are easier to read than those found in books. Some are in color. Buy the book How to Restore Your Datsun Z Car by Wick Humble. It will save you hours of searching for "how to" info. Focus on searching Hybridz as 99% of questions have already been addressed. Start bookmarking Z car parts suppliers. For SU carbs, parts and instructions go to Ztherapy. Buy the "Just SUs" video. Remember these are 40 year old cars and will need restoration to be safe and drivable. Join ClassicZCars.com website and search there as well. Become well informed about modifications before asking questions. People will be more inclined to answer informed questions Search the forums. Read all of the new member guidelines and FAQs Links: https://www.datsun-240z-upgrades.net/ Recommend the headlight relay harness http://zhome.com/ https://www.zcar.com/ https://www.classiczcars.com/ http://www.zcarparts.com/ http://www.arizonazcar.com/ http://www.jagsthatrun.com/index.html http://www.ztherapy.com/ http://www.xenonzcar.com/reference.html

T3 is developing a new rear caliper kit that will allow fitting of 15 inch wheels. The kit is being designed to compliment their Micro Big Brake front kit and it will have an integral parking brake. The owner says the rear kit should be out in a month or so.